Bituminous roofing material



Jan. 1, 19 6- ca. A. FASOLD ETAL 2,392,239

I BITUMINOUS ROOFING MATERIAL Filed May 1942 INVENTCRS GEORGE A. fksaLoH 0 W. 605/051? minute.-

Pa'tented Jan. 1, i946- BITUMINOUS ROOFING MATERIAL George A. Fasold,Mount Healthy, and Harold W. Greider, Wyoming, Ohio, assignors to ThePhilip Carey Manufacturing poration of Ohio Company, a cor- ApplicationMay 5, 1942, Serial No. 441,810

2 Claims.

This'invention relates to improvements inbituminousroofing,.particularly asphalt roofing having fibrous sheetsimpregnated with a waterproofing material and coated or mopped on one oropposite surfaces with adhesive bituminous layers. Granular material isusually applied to the weather exposed surface to give a decorative andartistic appearance as well as protect the' bituminous material from theactinic rays of the sun. In prepared asphalt roofing, the coating layeron the non-weather exposedside is usually dusted with talc, mica dust,or the like to render it non-adhesive, thereby preventing adhesionbetween the convolutions of a roll of a sheet'of the roofing material orbetween adjacent individual shingles or strips cut from a sheet of theroofing and stacked in bundles.

The fibrous base or foundation of prepared asphalt roofing is usually afelt or woven fabric impregnated with waterproofing asphalt. The asphaltis usually maintained at 225 to 400,F. in a saturating tank throughwhich the fabric is fed at a speed of about 100 to 3-50 lineal feet perRoofing felt will absorb about 100 to 200 per cent by weight of theimpregnating material, the amount absorbed depending on the porosity ofthe felt. Woven fabric will absorb a much smaller per cent of theimpregnating material. The aim is to impregnate the foundation or basefabric with as much waterproofing material as possible. While completeimpregnation of all the voids of the fabric or felt is desired, theconventional methods fail to achieve this perfection pock or crater-likeformations over the weather exposed surface. These marks not only marand disfigure the appearance of the roofing surface, but impair itsweather protecting qualities by exposing the fabric base or felt to theweather. Many of the granules on the weather exposed surface are pushedoff completely or loosened from the bituminous coating to which they areadhered. The blisters are of varying size and number, depending on thesize and number of voids in the felt, and their distribution through thefelt.

Blistering is'particularly prevalent in roofing that is used in the Gulfcoastal area in the southern part of the United States where there ishigh humidity and much rainfall in the summer months, and the roofingsurface temperatures may be as high as 170 F. Exposure of roofing tothese conditions and at the high summer temperature causes blistering ifthere are any pores or cells in the impregnated fabric to which theimpregnating material-has not penetrated.

Accordingly, the aim of this invention is to provide improvements inbituminized roofing wherein blisters 'are prevented from reaching anderupting through the weather exposed surface of roofing in which thefabric foundation is not completely impregnated. The weather exposedside is provided with an adherent blister barrier protecting meansthereon, and any moistureentrapped in the felt base of the roofing thatwould tend to form blisters in the roofing will be forced out from Tother points remote from the weather exposed of impregnation. Thatroofing material disclosed and claimed in Fasold et al., Patent2,159,586 and issued May 23-, 1939, comes the nearest to completeimpregnation of the fibrous foundation of any heretofore disclosed inthe art. It

has less than 0.5 per cent voids, as determined by soaking the roofingin water at 77 F. for twenty-'- four hours.

The reason for complete impregnation of the fabric foundation or base isto penetrate the impregnating material to all regions of the fabricthroughout its thickness and devoid it of all pores or cells. Pores andcells do not protect the fabric in those areas, but provide access forwater and moisture to be drawn in and collect or condense in the body ofthe roofing, and this collected moisture when heated causes a vaporpressure that deforms the coating layer and results in blisters beingformed. These blisters under continual pressure are sometimes forcedentirely through the coating layer on the weather exposed side, therebycausing numerous eruptions into Referring to the drawing in which likenumerals are used to designate like parts, prepared roofing, either inthe form of a sheet or strips into which the sheet is divided, iscomposed of a felt foundation 2, impregnated with a bituminouscomposition and coated on the the weather side with a bituminous layer3' of the same general character as the impregnating composition but ofhi her melting point and of harder consistency.

e underside or non-weather side of the foundation felt is usually andpreferably coated with a bituminous layer, such as 3' which is appliedto the weather side. Layer 3' is surfaced with any of the commonly usedgranular materials land the opposite or non-weather surface side,whether or any other finely divided materials suitable for 2 renderingthe non-weather exposed side non-adherent when the shingles are stackedor bundled.

A relatively thin adherent layer 5b is superposed on the weather side ofthe fo ndation felt between it and the bituminous coating to providea'blister barrier. This blister barrier layer has sumcient strength andtoughness for resistance to rupture from or appreciable deformation byany vapor pressure to which it may be subjected by reason of heat andmoisture in the roofing from weather conditions. The blister barrierlayer is preferably coextensive with the area of the rooting material sothat said roofing material is protected against blisters on all pointsof the weather exposed side of the foundation.

The thickness of the blister barrier layer may vary from about 0.0005 to0.015 of an inch and is usually of considerable less thicknessv than thebituminous coating 3. This composition blister barrier or resistantlayer is composed of shellac, a high melting point or hard asphalt, suchas gilsonite or the like, or any such adhesive material which issuiiiciently strong and tough so as not to be ruptured by any vaporpressure to which the roofing may be subjected. The composition materialcan be applied directly to the impregnated felt foundation and securedthereto by reason of its adherent character. The blister barrier orresistant layer is tougher and harder than the bituminous layer 3' orthe saturated felt and prevents any blister'breaking through orpenetrating to the overlay bituminous coating 3' over the blisterbarrier layer and on the weather exposed side or that to which thegranular surfacing material is applied.

While one embodiment has been disclosed and described indetail forcarrying the invention into effect, there may be various changes in thedetail of constructing the roofing material as well as in I the use ofmany other suitable adhesive materials for any blister barrier withinthe scope of the invention.

We claim:

1. A shingle comprising a base of fibrous material saturated withasphalt or the like, an asphaltic coating on the weather exposed side,mineral herent thermoplastic material interposed between the fibrousbase and the asphalt coating and adhered directly to the said fibrousbase, said membrane layer being impermeable to moisture vapor emittedfrom the fibrous base during exposure of the shingle to the weather.

GEORGE A. FASOLD. HAROLD W. GREIDER.

